Clinical studies and practice have shown that providing reduced pressure in proximity to a tissue site augments and accelerates the growth of new tissue at the tissue site. The applications of this phenomenon are numerous, but application of reduced pressure has been particularly successful in treating wounds. This treatment (frequently referred to in the medical community as “negative pressure wound therapy,” “reduced pressure therapy,” or “vacuum therapy”) provides a number of benefits, which may include faster healing and increased formulation of granulation tissue. Typically, when applied to open wounds, reduced pressure is applied to the tissue through a porous pad or other manifold device. The porous pad contains cells or pores that are capable of distributing reduced pressure to the tissue and channeling fluids that are drawn from the tissue. When applied subcutaneously, often the reduced pressure is delivered through a manifold that includes channels and openings in a reduced-pressure delivery apparatus.
A fistula at the tissue site can be problematic with respect to applying reduced pressure to the tissue site. In general terms, a “fistula” is an abnormal passage that leads from an abscess or hollow organ or part to the body surface or from one hollow organ or part to another and that may be surgically created to permit passage of fluids or secretions. As used herein, “fistula” includes, without limitation, enteric fistulas, enterocutaneous fistulas, and stomas. If a fistula were located at a tissue site that is a wound bed that is being treated and if reduced pressure were applied to the whole tissue site, including the fistula, effluent from the fistula would be drawn onto other portions of the tissue site. This would potentially cause slower healing or various issues. The situation may be more challenging with an intestinal fistula because effluent from an intestinal fistula can be corrosive to the wound bed.